1. Field of the Invention
The present invention relates to an environment control apparatus and, more particularly, to an environment control apparatus for cultivating plants.
2. Description of the Related Art
Cultivation of plants generally proceeds in an environment control box for mass propagation of seedlings. Typically, control of the temperature in the environment control box is achieved by using a mechanical switch of air conditioner type to touch a limit switch through thermal expansion and contraction by a refrigerant, causing the limit switch to be on or off at a contact point of the limit switch so as to start or stop operation of a compressor. However, the service life of the compressor is shortened due to frequent starting and stopping. Furthermore, the switch has an offset range in the temperature, failing to provide precise control of the temperature. Further, the compressor causes operation noise, and use of the refrigerant is not eco-friendly.
Use of thermoelectric cooling module in environmental control boxes has become a trend. The thermoelectric cooling modules convert electricity into heat to control the temperature in the environmental control boxes. However, several disadvantages still exist in actual use. Firstly, a cooler is required on the hot-surface-side of a thermoelectric cooling module to avoid the thermoelectric cooling module from being damaged due to overheat. Heat dissipation of the thermoelectric cooling module is, thus, an issue. Secondly, the heat at hot-surface-side of the thermoelectric cooling module is generally carried away by fins or a fan after the thermoelectric cooling module is electrified, failing to reuse the heat.